Detecting passing of unintended objects through throat of under-sink disposal

ABSTRACT

An under-sink disposal unit includes a motor, a disposal chamber, and a disposal throat. The disposal throat extends from the disposal chamber to an opening in a top of the disposal unit and defines a passageway through which objects pass into the disposal chamber for grinding. The disposal unit further includes a coil assembly including an arrangement of coils. The arrangement of coils is used to detect the passing of a metallic object in the passageway through the disposal throat. Furthermore, the arrangement of coils includes at least one coil having a loop that is oriented with respect to an axis of the passageway through the disposal throat such that objects passing through the disposal throat into the disposal chamber pass by and proximate to, but do not pass through, such loop. Preferably DC injection braking is used to stop the motor upon detection of a metallic object.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of, and claims the benefit ofpriority under 35 U.S.C. 120 to, U.S. national stage patent applicationSer. No. 14/896,435, filed Jun. 20, 2015, corresponding toPCT/US2015/036847, which in turn is a nonprovisional of, and claims thebenefit of priority under 35 U.S.C. 119 to, U.S. provisional patentapplication 62/165,887, filed May 22, 2015. The disclosure of theprovisional patent application is incorporated by reference herein.

COMPUTER PROGRAM LISTING

Submitted concurrently herewith via the USPTO's electronic filingsystem, and incorporated herein by reference, are computer program filesincluding instructions, routines, and/or other contents of severalcomputer programs. A table setting forth the name and size of filesincluded in the computer program listing is included below.

File Name Creation Date File Size (bytes) ASCIFY.txt 5/22/2015 15:1837473 FILES.TXT 5/22/2015 15:18 1289487 readme.txt 5/22/2015 15:18 2591

One of these files, “readme.txt”, contains instructions for extractinginformation from another of the files. This other file represents acompressed binary file that has been converted to ascii format. Thisfile can be converted back to a compressed .zip archive utilizing anassembly conversion program source code for which is contained in“ascify.txt”. The readme file includes instructions for compiling andrunning this conversion program, and instructions for converting theother text files to a compressed, binary file.

This compressed, binary file includes eDrawings files representingcomputer models. These files can be opened using eDrawings softwareavailable from Dassault Systémes SOLIDWORKS Corp.

COPYRIGHT STATEMENT

All of the material in this patent document is subject to copyrightprotection under the copyright laws of the United States and othercountries. The copyright owner has no objection to the facsimilereproduction by anyone of the patent document or the patent disclosure,as it appears in official governmental records but, otherwise, all othercopyright rights whatsoever are reserved.

BACKGROUND OF THE INVENTION

The present invention generally relates to under-sink disposals. Suchdisposals are commonly found in most U.S. homes, and are designed toshred organic material prior to entering a sewer system. A conventionalunder-sink disposal is shown, for example, in FIG. 17 of the '887provisional application, a disposal chamber assembly of which is shownin FIG. 18 of the '887 provisional application.

Such disposals are not designed to handle bottle caps, jar lids, orutensils such as a knife, fork, or spoon, let alone the occasional pieceof jewelry, such as a wedding ring. Indeed, when such items areinadvertently dropped or otherwise fall into the disposal, the disposalbreaks, the item is damaged or destroyed, or both.

In view of this, it is believed that a need exists for improvement inunder-sink disposals in order to address the situation in which autensil or other metallic object—including non-ferrous object—isaccidentally dropped into or otherwise inadvertently enters thedisposal. Such need is addressed in the solutions disclosed in U.S. Pat.Nos. 8,584,976 and 8,740,115, each of which is incorporated herein byreference; however, it is believed that additional improvements can yetbe made in the manner and efficiency with which metallic objects aredetected in the disposal, such as further focusing on filtering of noiseand shielding of unwanted environmental effects. This—and otherneeds—are believed to be addressed by one or more aspects and featuresof the present invention.

SUMMARY OF THE INVENTION

The present invention generally relates to apparatus and methods fordetecting unintended objects in under-sink disposals and, in particular,to apparatus and methods for detecting unintended objects—including bothferrous and non-ferrous objects—that fall through a throat of anunder-sink disposal. Moreover, the present invention includes manyaspects and features.

In an aspect of the invention, an under-sink disposal unit includes amotor, a disposal chamber, and a disposal throat. The disposal throatextends from the disposal chamber to an opening in a top of the disposalunit and defines a passageway through which objects pass into thedisposal chamber for grinding. The disposal unit further includes a coilassembly comprising an arrangement of coils. The arrangement of coils isused to detect the passing of a metallic object in the passagewaythrough the disposal throat. Furthermore, the arrangement of coilscomprises at least one coil having a loop that is oriented with respectto an axis of the passageway through the disposal throat such thatobjects passing through the disposal throat into the disposal chamberpass by and proximate to, but do not pass through, such loop.

In a feature, the loop of the at least one coil of the arrangementcomprises multiple windings of an electrically conductive wire.

In a feature, the disposal unit further includes a collar extendingaround the disposal throat to which the arrangement of coils aresecured. In various further features: the collar completely encompassesthe disposal throat; the collar is generally commensurate in extent withthe disposal throat; the collar of the coil assembly extends between alocking ring whereat the disposal unit is attached to the underneath ofa sink, and a top of the disposal chamber; the collar extends around thedisposal throat along the entire extent of the disposal throat betweenthe disposal chamber and the top of the disposal unit; and the collarextends around the disposal throat along the entire extent of thedisposal throat along which the passageway is defined.

In a feature, the arrangement of coils includes: a first coil comprisinga loop that is oriented with respect to an axis of the passagewaythrough the disposal throat such that objects passing through thedisposal throat into the disposal chamber pass by and proximate to, butdo not pass through, the loop of the first coil; a second coilcomprising a loop that is oriented with respect to the axis such thatobjects passing through the disposal throat into the disposal chamberpass by and proximate to, but do not pass through, the loop of thesecond coil; and a third coil comprising a loop that is oriented withrespect to the axis such that objects passing through the disposalthroat into the disposal chamber pass through the loop of the thirdcoil. Moreover, the third coil preferably further comprises anadditional loop that is oriented with respect to the axis such thatobjects passing through the disposal throat into the disposal chamberpass through the additional loop of the third coil, with one of theloops being located proximate a top of the coil assembly and the otherloop being located proximate a bottom of the coil assembly. Stillfurther, the loops of the third coil preferably are electricallyconnected in series, and each loop of the third coil preferablycomprises multiple windings of an electrically conductive wire. In atleast some embodiments, the third coil is a transmit coil, and the firstand second coils are receiver coils. The first and second coils alsopreferably are not electrically connected in series or parallel.Furthermore, each coil preferably is respectively connected to acontroller comprising circuitry used to detect, via the coil assembly,the passing of a metallic object in the passageway through the disposalthroat. In further to this respect, the controller preferably isconfigured to cut power to the motor of the disposal unit upon thedetecting of the passing of a metallic object in the passageway throughthe disposal throat; or the motor is an alternating current motor, thedisposal unit further includes an AC to DC converter, and the controlleris configured to cause current to the motor to switch from alternatingcurrent to direct current from the AC to DC converter upon the detectingof the passing of a metallic object in the passageway through thedisposal throat, whereby DC injection braking is performed.

In another feature, the arrangement of coils comprises of a plurality ofcoils, each of which includes a loop that is oriented with respect to anaxis of the passageway through the disposal throat such that objectspassing through the disposal throat into the disposal chamber pass byand proximate to, but do not pass through, such loop.

In another feature, the arrangement of coils comprises of a plurality ofcoils, none of which includes a loop that is oriented with respect to anaxis of the passageway through the disposal throat such that objectspassing through the disposal throat into the disposal chamber passthrough such loop.

In another aspect, a method of controlling operation of a disposal unitincludes the steps of: detecting the passing of a metallic objectthrough a passageway of a disposal throat; and switching fromalternating current to direct current for powering a motor of thedisposal unit upon the detection of a metallic object passing throughthe disposal throat of the disposal unit, whereby DC injection brakingis performed.

In a feature of this aspect, step (a) of the method is performed when auser activated switch for running the motor of the disposal unit is inthe on position. Furthermore, step (a) of the method is performed onlywhen the user activated switch is in the on position; or alternatively,step (a) of the method is further performed when the user activatedswitch is in the off position when power is otherwise supplied to thecontroller.

In still yet another aspect, a method of installing an under-sinkdisposal unit includes the steps of: providing an under-sink disposalunit as disclosed herein; connecting power to the motor of the disposalunit such that the power is toggled by a user activated switch; andconnecting power to electronics of the under-sink disposal unit thatactively detects passing of a metallic object through a disposal throatof the disposal unit, and that cuts power to the motor of the disposalunit upon the detection of a metallic object passing through a disposalthroat of the disposal unit.

In another aspect, a method of installing an under-sink disposal unitincludes the steps of: providing an under-sink disposal unit asdisclosed herein; connecting power to the motor of the disposal unitsuch that the power is toggled by a user activated switch; andconnecting power to electronics of the under-sink disposal unit thatactively detects passing of a metallic object through a disposal throatof the disposal unit, and that switches from alternating current todirect current in powering the motor of the disposal unit upon thedetection of a metallic object passing through a disposal throat of thedisposal unit, whereby DC injection braking is performed.

In an aspect, an under-sink disposal installation comprises a sink; andan under-sink disposal unit as disclosed herein.

In another aspect of the invention, an under-sink disposal installationcomprises a sink; and an under-sink disposal unit comprising: (i) amotor, (ii) a disposal chamber, (iii) a disposal throat, wherein thedisposal throat extends from the disposal chamber to an opening in a topof the disposal unit and defines a passageway through which objects passinto the disposal chamber for grinding, and (vi) a coil assemblycomprising an arrangement of coils. The arrangement of coils is used todetect the passing of a metallic object in the passageway through thedisposal throat, and the arrangement of coils comprises at least onecoil having a loop that is oriented with respect to an axis of thepassageway through the disposal throat such that objects passing throughthe disposal throat into the disposal chamber pass by and proximate to,but do not pass through, such loop.

In a feature, the disposal unit further comprises a cowling enclosingthe motor, the disposal chamber, and the disposal throat.

Still further features of the present invention are disclosed in theincorporated provisional application, including in the models of theComputer Program Listing of the Appendix of the '887 provisionalapplication; and in the incorporated patents.

Other aspects of the invention comprise methods of using apparatus ofthe foregoing aspects.

Still other aspects comprise kits for up-fitting conventional disposalsystems. Alternatively, one or more of the foregoing aspects andfeatures can be integrated into a disposal system as manufactured andprovided by an “OEM”.

In addition to the aforementioned aspects and features of the presentinvention, it should be noted that the present invention furtherencompasses the various possible combinations and subcombinations ofsuch aspects and features. Thus, for example, any aspect may be combinedwith an aforementioned feature in accordance with the present inventionwithout requiring any other aspect or feature.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more preferred embodiments of the present invention now will bedescribed in detail with reference to the accompanying drawings, whereinthe same elements are referred to with the same reference numerals.

FIG. 1 is schematic illustration of an isometric view of an under-sinkdisposal unit in accordance with a preferred embodiment of the presentinvention, wherein a wall of a cowling base of the unit is partiallycutaway, and wherein the motor contained in the cowling base has beenomitted.

FIG. 2 is a schematic illustration of an isometric view of the disposalchamber assembly, the coil assembly, a gasket, and a locking ring of theunder-sink disposal unit of FIG. 1.

FIG. 3 is a schematic illustration similar to that of FIG. 2, whereinthe coil assembly has been omitted.

FIG. 4 is a schematic illustration similar to that of FIG. 3, whereinthe gasket and locking ring have been omitted and only a subassemblycomprising a disposal chamber, a disposal throat, and a dampener of theunder-sink disposal unit of FIG. 1 are shown.

FIG. 5 is a schematic illustration of a front elevational view of thesubassembly of FIG. 4 comprising the disposal chamber, the disposalthroat, and the dampener.

FIG. 6 is a schematic illustration of a right elevational view of thesubassembly of FIG. 4 comprising the disposal chamber, the disposalthroat, and the dampener.

FIG. 7 is a schematic illustration of a back elevational view of thesubassembly of FIG. 4 comprising the disposal chamber, the disposalthroat, and the dampener.

FIG. 8 is a schematic illustration of a left elevational view of thesubassembly of FIG. 4 comprising the disposal chamber, the disposalthroat, and the dampener.

FIG. 9 is a schematic illustration of a bottom view of the subassemblyof FIG. 4 comprising the disposal chamber, the disposal throat, and thedampener.

FIG. 10 is a schematic illustration of a top view of the subassembly ofFIG. 4 comprising the disposal chamber, the disposal throat, and thedampener.

FIG. 11 is a schematic illustration similar to that of FIG. 2, whereinall but the coil assembly has been omitted.

FIG. 12 is a schematic illustration of an isometric view of the coilsand brackets of the coil assembly of the under-sink disposal unit ofFIG. 1.

FIG. 13 is a side elevational view of the under-sink disposal unit ofFIG. 1.

FIG. 14 is schematic illustration of an isometric, exploded view of theunder-sink disposal unit of FIG. 1.

FIG. 15 is a circuit diagram for stopping operation of the disposal unitin accordance with a preferred embodiment of the present invention,wherein power is supplied to the motherboard and control circuitry onlywhen the user activated switch is in the ‘on’ position.

FIG. 16 is a circuit diagram for stopping operation of the disposal unitin accordance with another preferred embodiment of the presentinvention, wherein power is supplied to the motherboard and controlcircuitry regardless of the position of the user activated switch.

FIG. 17 is a circuit diagram in accordance with a preferred embodimentof the present invention, wherein normal powering of the motor of thedisposal unit is represented.

FIG. 18 is the circuit diagram of FIG. 17, wherein DC injection brakingis represented for stopping the motor of the disposal unit followingdetection of a metallic object passing through the throat of thedisposal unit.

DETAILED DESCRIPTION

As a preliminary matter, it will readily be understood by one havingordinary skill in the relevant art (“Ordinary Artisan”) that theinvention has broad utility and application. Furthermore, any embodimentdiscussed and identified as being “preferred” is considered to be partof a best mode contemplated for carrying out the invention. Otherembodiments also may be discussed for additional illustrative purposesin providing a full and enabling disclosure of the invention.Furthermore, an embodiment of the invention may incorporate only one ora plurality of the aspects of the invention disclosed herein; only oneor a plurality of the features disclosed herein; or combination thereof.As such, many embodiments are implicitly disclosed herein and fallwithin the scope of what is regarded as the invention.

Accordingly, while the invention is described herein in detail inrelation to one or more embodiments, it is to be understood that thisdisclosure is illustrative and exemplary of the invention, and is mademerely for the purposes of providing a full and enabling disclosure ofthe invention. The detailed disclosure herein of one or more embodimentsis not intended, nor is to be construed, to limit the scope of patentprotection afforded the invention in any claim of a patent issuing herefrom, which scope is to be defined by the claims and the equivalentsthereof. It is not intended that the scope of patent protection affordedthe invention be defined by reading into any claim a limitation foundherein that does not explicitly appear in the claim itself.

Thus, for example, any sequence(s) and/or temporal order of steps ofvarious processes or methods that are described herein are illustrativeand not restrictive. Accordingly, it should be understood that, althoughsteps of various processes or methods may be shown and described asbeing in a sequence or temporal order, the steps of any such processesor methods are not limited to being carried out in any particularsequence or order, absent an indication otherwise. Indeed, the steps insuch processes or methods generally may be carried out in variousdifferent sequences and orders while still falling within the scope ofthe invention. Accordingly, it is intended that the scope of patentprotection afforded the invention is to be defined by the issuedclaim(s) rather than the description set forth herein.

Additionally, it is important to note that each term used herein refersto that which the Ordinary Artisan would understand such term to meanbased on the contextual use of such term herein. To the extent that themeaning of a term used herein-as understood by the Ordinary Artisanbased on the contextual use of such term-differs in any way from anyparticular dictionary definition of such term, it is intended that themeaning of the term as understood by the Ordinary Artisan shouldprevail.

Regarding applicability of 35 U.S.C. 112, paragraph 6 or subsection (f),no claim element is intended to be read in accordance with thisstatutory provision unless the explicit phrase “means for” or “step for”is actually used in such claim element, whereupon this statutoryprovision is intended to apply in the interpretation of such claimelement.

Furthermore, it is important to note that, as used herein, “a” and “an”each generally denotes “at least one,” but does not exclude a pluralityunless the contextual use dictates otherwise. Thus, reference to “apicnic basket having an apple” describes “a picnic basket having atleast one apple” as well as “a picnic basket having apples.” Incontrast, reference to “a picnic basket having a single apple” describes“a picnic basket having only one apple.”

When used herein to join a list of items, “or” denotes “at least one ofthe items,” but does not exclude a plurality of items of the list. Thus,reference to “a picnic basket having cheese or crackers” describes “apicnic basket having cheese without crackers”, “a picnic basket havingcrackers without cheese”, and “a picnic basket having both cheese andcrackers.” When used herein to join a list of items, “and” denotes “allof the items of the list.” Thus, reference to “a picnic basket havingcheese and crackers” describes “a picnic basket having cheese, whereinthe picnic basket further has crackers,” as well as describes “a picnicbasket having crackers, wherein the picnic basket further has cheese.”

Referring now to the drawings, one or more preferred embodiments of theinvention are next described. The following description of one or morepreferred embodiments is merely exemplary in nature and is in no wayintended to limit the invention, its implementations, or uses.

Turning now to FIG. 1, an under-sink disposal unit 100 in accordancewith a preferred embodiment of the present invention is schematicallyillustrated in isometric view. It will be appreciated that in FIG. 1, awall of a cowling base 102 of the unit 100 is partially cutaway, and theAC motor that normally would be found contained in the cowling base hasbeen omitted in the illustration.

FIG. 2 is a schematic illustration of an isometric view of the disposalchamber assembly 106, the coil assembly 108, the gasket 110, and thelocking ring 112 of the under-sink disposal unit 100.

FIG. 3 is a schematic illustration similar to that of FIG. 2, whereinthe coil assembly 108 has been omitted.

FIG. 4 is a schematic illustration similar to that of FIG. 3, whereinthe gasket 110 and locking ring 112 have been omitted, and wherein onlythe disposal chamber assembly 106 is shown. The disposal chamberassembly 106 comprises a disposal throat 114, and a dampener 116, and adisposal chamber 118.

FIG. 5 is a schematic illustration of a front elevational view of thedisposal chamber subassembly 106 comprising the disposal throat 114, thedampener 116, and the disposal chamber 118; FIG. 6 is a schematicillustration of a right elevational view of the subassembly 106; FIG. 7is a schematic illustration of a back elevational view of thesubassembly 106; FIG. 8 is a schematic illustration of a leftelevational view of the subassembly 106; FIG. 9 is a schematicillustration of a bottom view of the subassembly 106; and FIG. 10 is aschematic illustration of a top view of the subassembly 106.

FIG. 11 is a schematic illustration similar to that of FIG. 2, whereinall but the coil assembly 108 has been omitted.

The coil assembly 108 comprise a collar 120, four brackets122,124,126,128, a first coil 130 of conductive wire, and second coils132,134 of conductive wires. The first coil 130 is arranged in twoconcentric loops relative to an axis 500 of the passageway of thedisposal throat 114, with one being proximate the top of the collar 120and the other being proximate the bottom of the collar 120, each loopcomprising multiple wrappings of the wire that define a bundle.Accordingly, it will be appreciated that objects passing through thedisposal throat 114 pass through the loops of the first coil 130.Moreover, the two loops of the first coil 130 are electrically connectedin series, effectively making them a continuous line. The first coil 130preferably serves as the transmit coil.

In contrast, the coils 132,134 serve as receiver coils, and eachcomprises a bundled loop with the coils 132,134 being located onopposite sides of the disposal throat 120. Unlike the loops of the coil130, the loops of coils 132,134 are electrically separate and are notconcentric relative to the axis 500 of the passageway of the disposalthroat 114. Instead, the loops of the coils 132,134 are orthogonallyoriented to such axis 500, whereby objects passing through the disposalthroat 114 pass by and proximate to, but do not pass through, the loopsof the coils 132,134.

FIG. 12 is a schematic illustration of an isometric view of the coils130,132,134 and brackets 122,124,126,128 of the coil assembly 108 of theunder-sink disposal unit 100.

FIG. 13 is a side elevational view of the under-sink disposal unit 100.The cowling base 102 and cowling cap 104 enclose the disposal chamberassembly 106 and the coil assembly 108, as well as a motor of thedisposal unit 100, which motor has been omitted from the drawings forclarity of illustration.

It will be appreciated that the coil assembly 108 is located about thedisposal throat 114 at an elevation above the disposal chamber 118whereby detection of a metallic object utilizing the coil assembly 108will provide a lead time in which to cutoff AC power to the motor beforethe metallic object reaches the grinding mechanism located within thedisposal chamber 118 of the disposal unit 100. Further operation of thedisposal is disclosed in greater detail below with reference to FIGS.15-18.

FIG. 14 is schematic illustration of an isometric, exploded view of theunder-sink disposal unit 100 of FIG. 1.

FIG. 15 is a circuit diagram 600 for stopping operation of a disposalunit in accordance with a preferred embodiment of the present invention.As represented in this circuit diagram, electrical power in the form ofalternating current (AC) is provided via line voltage 602, which poweris turned on to the disposal unit by a user activated switch 604. Whenthe user activated switch is turned on, both the electronics of anelectronics box 606 and the motor 608 of the disposal unit are powered;when the user activated switch is turned off, neither the electronicsnor the motor is powered. In particular, the line voltage powers amotherboard 610 in an electronics box that includes a controller via apower supply 611, and the line voltage powers a motor of the disposalunit indicated by ‘M’ in FIG. 15 via motor power line 615. Thecontroller is connected to and disposed in electronic communicationswith a coil assembly 601 of the disposal unit via the signal wire bundle612. When a metallic object is detected passing through the throat ofthe disposal unit, which is detected via the coil assembly, thecontroller cuts power to the motor via the normally closed (NC) relay614. A 15 amp, 120 volt fuse 613 precedes the relay. An LED 616 isrepresented in the circuit diagram that is activated to indicate thatthe controller has cut power to the motor of the disposal unit.

Continuing with reference to FIG. 15, the coil assembly shown isrepresentative of a three-coil assembly such as, for example, coilassembly 108 of FIG. 11. Such a coil assembly is believed to beparticularly well suited for detecting metallic objects, includingnon-ferrous metallic objects, and represents a preferred coil assemblyin accordance with the present invention.

The power to the motor of the disposal unit is restored by moving theuser activated switch to the off position and then back to the onposition. From the circuit diagram of FIG. 15, it will be appreciatedthat the power is supplied to the motherboard and control circuitry onlywhen the user activated switch is in the on position and, consequently,a metallic object passing through the throat of the disposal will not bedetected when the user activated switch is in the off position.

It is believed that it is advantageous to be able to detect when ametallic object passes through the disposal throat even when the motorof the disposal unit is not running. Operation of a disposal unit inaccordance with the circuit diagram 700 of FIG. 16 is believed toprovide such an advantage; however, the installation of a disposal unitthat operates in accordance with the circuit diagram of FIG. 15 isbelieved to simpler than the installation of the disposal unit thatoperates in accordance with the circuit diagram of FIG. 16.

With regard to the circuit diagram of FIG. 16, the line voltage 702 isshown as powering the electronics of the electronics box 706 includingthe motherboard 710 prior to the user activated switch 704. The circuitdiagram is similar to that of FIG. 15, and differs in part in that thepower supply for the detection board is simply moved to a permanentlyinstalled line voltage. All other functions generally remain the same,as will be appreciated from review of the circuit diagram 700. The useractivated switch is used to toggle power to the motor 708 of thedisposal unit by a user during normal operation of the disposal unit.When a metallic object is detected as passing through the throat of thedisposal, the controller breaks the electrical path supplying power tothe motor at the normally closed (NC) relay 714. The passing of ametallic object is detected even when the user activated switch is inthe off position with the motor off during times when a user is notusing or intending to use the disposal unit. The LED 716 is illuminatedto indicate that the passing of a metallic object has been detected,whereby a user will know that the failure of the motor to start when theswitch is turned on is a result of the controller and not a malfunctionof the disposal unit or general loss of electric power. A reset (notshown) preferably is provided by which a user resets the controller andthe relay is moved to the normally closed position for powering of themotor when the user activated switch is turned on.

FIGS. 17 and 18 are circuit diagrams showing powering of the disposalunit and the use of DC injection braking for stopping the motor of thedisposal unit when a metallic object passing through the throat of thedisposal unit has been detected. The DC injection braking is done as analternative to cutting power to the motor of the disposal, asrepresented in the circuit diagrams of FIGS. 15 and 16. The circuitdiagrams of FIGS. 17 and 18 thus represent the portion of the circuitdiagrams of FIGS. 15 and 16, including the NC relay, which would bereplaced when DC injection braking is utilized. In this regard, thecontroller controls switching between Path A (for normal powering of themotor, as shown in FIG. 17) and Path B (for DC injection braking asshown in FIG. 18). During normal operation, the alternating current 802from the wall power enables the AC motor 808 to spin. The electricalpathway is through Path A. During DC injection braking, the path ofelectricity is diverted through parallel Path B, wherein the AC currentpasses through a current converter 820 changing the AC current to DCcurrent. It is believed that DC injection braking would further reduceif not completely prevent damage to a metallic object by activelyhalting the grinding mechanism rather than merely allowing the grindingmechanism to passively come to a stop after cutting power to the motorvia the NC relay.

With particular regard to functioning of the electronics, numerousmethods can be utilized in the circuitry for detecting metallic objects.The primary method of metal detection is to detect a disturbance in amagnetic field. Preferably, the method used in preferred embodiments ofthe disposal unit comprises a “pulsed wave” system. The primarycomponents utilized in this type of system are at least two coils, i.e.,one or more transmit coil(s) and receiver coil(s)); a timer; anamplifier; and a comparing circuit. The fundamental operation is asfollows.

The timer activates current to pass through the transmit coil(s) throughthe amplifier. This allows for enough current to pass through thetransmit coil(s) to generate a relatively large magnetic field about thetransmit coil(s). The timer then shuts off the current through thetransmit coil(s). The comparing circuit then compares the measuredcurrent from the receive coils to a known or expected value. If there isa conductive object within the filed energized by the transmit coil(s),eddy currents will be developed within the object. Once current throughthe transmit coil(s) is shut off, the eddy currents in the metallicobject will continue to emit a magnetic field until stopped by theinternal resistance of the metallic object. The magnetic field producedfrom the eddy currents in the metallic object will induce a current inthe receive coils. The current registers as a voltage. If a metallicobject is within the field and induces a current on the receive coils,then the voltage of the receive coils will deviate from the expectedvalue and it can be determined that a metallic object is within thefield of detection.

In the disposal unit, the controller preferably is a microcontrollerwhich acts, among other things, as a timer. The microcontroller controlsthe current through the transmit coil(s). In particular, themicrocontroller cannot supply the necessary current to the transmitcoil(s) so an amplifier circuit is provided to drive the transmitcoil(s). The two receiver coils are provided, with a first beingconnected to the positive terminal of a summing circuit and the otherbeing attached to the negative terminal. Under normal operatingconditions, the two receive coils read the same response and cancel eachother out; however, if a conductive object passes through the field ofthe transmitter (like a metallic object passing through the drainthroat), then one of the coils offsets the other and a deflection fromzero occurs. If this deflection is greater than the statistical noisefloor, then the microcontroller reads a detection of an unintendedobject passing through the disposal throat. Upon reading a detection,the microcontroller sends a signal to the power relay. The power relayis located electrically between the wall power and the motor of thedisposal. When signaled by the microcontroller, the relay opens andpowering of the motor of the disposal is stopped.

Based on the foregoing description, it will be readily understood bythose persons skilled in the art that the present invention issusceptible of broad utility and application. Many embodiments andadaptations of the present invention other than those specificallydescribed herein, as well as many variations, modifications, andequivalent arrangements, will be apparent from or reasonably suggestedby the present invention and the foregoing descriptions thereof, withoutdeparting from the substance or scope of the present invention.

Accordingly, while the present invention has been described herein indetail in relation to one or more preferred embodiments, it is to beunderstood that this disclosure is only illustrative and exemplary ofthe present invention and is made merely for the purpose of providing afull and enabling disclosure of the invention. The foregoing disclosureis not intended to be construed to limit the present invention orotherwise exclude any such other embodiments, adaptations, variations,modifications or equivalent arrangements, the present invention beinglimited only by the claims appended hereto and the equivalents thereof.

What is claimed is:
 1. An under-sink disposal unit, comprising a motor,a disposal chamber, and a disposal throat, wherein the disposal throatextends from the disposal chamber to an opening in a top of the disposalunit and defines a passageway through which objects pass into thedisposal chamber for grinding, and further comprising (a) a coilassembly comprising an arrangement of coils, (b) wherein the arrangementof coils is used to detect the passing of a metallic object in thepassageway through the disposal throat, and (c) wherein the arrangementof coils comprises, (i) a first coil comprising a loop that is orientedwith respect to an axis of the passageway through the disposal throatsuch that objects passing through the disposal throat into the disposalchamber pass by and proximate to, but do not pass through, the loop ofthe first coil, (ii) a second coil comprising a loop that is orientedwith respect to the axis such that objects passing through the disposalthroat into the disposal chamber pass by and proximate to, but do notpass through, the loop of the second coil, and (iii) a third coilcomprising a loop that is oriented with respect to the axis such thatobjects passing through the disposal throat into the disposal chamberpass through the loop of the third coil.
 2. The under-sink disposal unitof claim 1, wherein at least one loop of the arrangement of coilscomprises multiple windings of an electrically conductive wire.
 3. Theunder-sink disposal unit of claim 1, further comprising a collarextending around the disposal throat to which the arrangement of coilsare secured.
 4. The under-sink disposal unit of claim 3, wherein thecollar completely encompasses the disposal throat.
 5. The under-sinkdisposal unit of claim 3, wherein the collar is generally commensuratein extent with the disposal throat.
 6. The under-sink disposal unit ofclaim 3, wherein the collar of the coil assembly extends between alocking ring whereat the disposal unit is attached to the underneath ofa sink, and a top of the disposal chamber.
 7. The under-sink disposalunit of claim 3, wherein the collar extends around the disposal throatalong the entire extent of the disposal throat between the disposalchamber and the top of the disposal unit.
 8. The under-sink disposalunit of claim 3, wherein the collar extends around the disposal throatalong the entire extent of the disposal throat along which thepassageway is defined.
 9. The under-sink disposal unit of claim 1,wherein the third coil further comprises an additional loop that isoriented with respect to the axis such that objects passing through thedisposal throat into the disposal chamber pass through the additionalloop of the third coil.
 10. The under-sink disposal unit of claim 9,wherein the loops of the third coil are electrically connected inseries.
 11. The under-sink disposal unit of claim 9, wherein each loopof the third coil comprises multiple windings of an electricallyconductive wire.
 12. The under-sink disposal unit of claim 9, whereinthe third coil is a transmit coil, and wherein the first and secondcoils are receiver coils.
 13. The under-sink disposal unit of claim 9,wherein the first and second coils are not electrically connected inseries or parallel.
 14. The under-sink disposal unit of claim 9, whereineach coil is respectively connected to a controller comprising circuitryused to detect, via the coil assembly, the passing of a metallic objectin the passageway through the disposal throat.
 15. The under-sinkdisposal unit of claim 14, wherein the controller is configured to cutpower to the motor of the disposal unit upon the detecting of thepassing of a metallic object in the passageway through the disposalthroat.
 16. The under-sink disposal unit of claim 14, wherein the motoris an alternating current motor, wherein the disposal unit furthercomprises an AC to DC converter, and wherein the controller isconfigured to cause current to the motor to switch from alternatingcurrent to direct current from the AC to DC converter upon the detectingof the passing of a metallic object in the passageway through thedisposal throat, whereby DC injection braking is performed.
 17. A methodof installing an under-sink disposal unit, comprising: (a) providing theunder-sink disposal unit of claim 1; (b) connecting power to the motorof the disposal unit such that the power is toggled by a user activatedswitch; and (c) connecting power to electronics of the under-sinkdisposal unit that actively detects passing of a metallic object througha disposal throat of the disposal unit, and that cuts power to the motorof the disposal unit upon the detection of a metallic object passingthrough a disposal throat of the disposal unit.
 18. A method ofinstalling an under-sink disposal unit, comprising: (a) providing anunder-sink disposal unit of claim 1; (b) connecting power to the motorof the disposal unit such that the power is toggled by a user activatedswitch; and (c) connecting power to electronics of the under-sinkdisposal unit that actively detects passing of a metallic object througha disposal throat of the disposal unit, and that switches fromalternating current to direct current in powering the motor of thedisposal unit upon the detection of a metallic object passing through adisposal throat of the disposal unit, whereby DC injection braking isperformed.
 19. An under-sink disposal installation, comprising: (a) asink; and (b) an under-sink disposal unit comprising, (i) a motor, (ii)a disposal chamber, (iii) a disposal throat that extends from thedisposal chamber to an opening in a top of the disposal unit and definesa passageway through which objects pass into the disposal chamber forgrinding, and (iv) a coil assembly comprising an arrangement of coilsused to detect the passing of a metallic object in the passagewaythrough the disposal throat, the arrangement of coils comprising, (A) afirst coil comprising a loop that is oriented with respect to an axis ofthe passageway through the disposal throat such that objects passingthrough the disposal throat into the disposal chamber pass by andproximate to, but do not pass through, the loop of the first coil, (B) asecond coil comprising a loop that is oriented with respect to the axissuch that objects passing through the disposal throat into the disposalchamber pass by and proximate to, but do not pass through, the loop ofthe second coil, and (C) a third coil comprising a loop that is orientedwith respect to the axis such that objects passing through the disposalthroat into the disposal chamber pass through the loop of the thirdcoil.
 20. The under-sink disposal installation of claim 19, wherein thedisposal unit further comprises a cowling enclosing the motor, thedisposal chamber, and the disposal throat.